Barometric fuze



whose ends are xed to the inner surfaces of the casing I and whose mid-portion bears against the block 4 to force it inwards as the screw 6 is slackened. The lever 2 has a tail portion 'l and both members are mounted upon a common pivot 3 carried by the radially movable block 4. The tail member 'I makes contact with the inclined upper edge of a circular cam 8 formed integral with a disc 9 adapted .to be fixed centrally within the base I of the casing I by means of a nut I I which engages a screw-threaded extension I2 on the disc, the arrangement enabling rotation of the base of the casing to vary the position of the cam to cause the inner end of the lever 2 to be lifted or lowered between the positions shown in Figs. 1 and 4.

The base part I0 of the casing is rotatable-and i,

has a scale of altitudes engraved on it (Fig. The interior of the extension I2 is screw-threaded to engage the spindle I3 of a wind vane I4 which operates in the same manner as described in the said prior application, Ythe spindle I3 passing through the lever 2 whose inner end is forked at I5 as shown in Fig. 2.

To ensure that the striker mechanism I1 shown in Figs. 1 and 4 will operate only at the exact predetermined height above sea level and avoid deviations due to the use of aneroid capsules I8 of varying sensitivity, the scale of altitudes on each device is accommodated to each capsule as a nal operation inthe production of the device. To this end two adjustments are made after the fuze has been assembled and before it is associated Ywith a charge to be exploded or ignited. The first of the said adjustments is made at the zero setting of the scale by adjusting the length of the casing I of the fuze and, as'thls is the ground level setting, this adjustment can be made at atmospheric pressure. The adjustment is effected by using slotted holes for screws 2I which x the outer casing I to the casting 23. The position of the zero mark of the scale on the rotatable member I0 is determined bythe tail portion l of the stop lever 2. This tail piece rests on the cam 8 and lies at right angles to the axis of the fuze when the fuze is set at zero. That is, when this tail portion 1 is lifted by the rotatable cam '8 into the same horizontal plane'as the axis of the member 3. The stop is thereafter set for the iiring height desired by the user by the part I0 of the fuze being rotated to some `point' at the other end of the scale, say the point marked 10,000 ft., and the fuze is adjusted by rotating the screw 6 until the capsule causes the iiring pin I9 to operate under a pressure equivalent to that at an altitude of 10,000 ft. This adjustment alters the ratio of the leverage between the stop lever 2 and its tail piece 1 which 'rests on the cam, and thus alters the position of Owing to the fact that the tail the stop lever. member I was at Yright angles to the axis of the fuze in the Zero setting position the adjustment will not affect `the zero adjustment so that two points on the scale will be correct. As the relation of the expansion 0f -each individual capsule to the reduction in pressure is very nearly linear, the calibration of a fuze device set inthe manner described `will also be substantially correctv at all other points on the scale.

In the operation of ther device above described, the release of the bomb or the like from the aircraft causes the wind'vaneV to vrotate andwithdraw the spindle I3 from contact with the bellows plate 2l] until the continued rotation removes Vthe spindle altogether fromv the extension I2 vand the wind vanefalls away.' 4The removal of the spindle 4 allows a spring 22 acting on the casing to move the bellows as a whole downwards until its plate makes contact with the stop lever 2 so that the device is in the armed condition as described in my aforesaid prior application. As the bomb or pyrotechnic device descends to regions of higher pressure, the bellows contracts and withdraws the release pin and enables the striker to operate. By employing a settable arrangement according to the present invention; which enablesthe sensitivity of any particular capsule to be taken into account, it is ensured that the striker will operate Y exactly at the predetermined height above sea level.

- Iclaim:

1. A barometric fuze device comprising a casing 'embodying relatively adjustable sections, a firing pin and releasable restraining means therefor mounted in one of said sections, an aneriod capsule carrying means movable thereby for controlling said restraining means, a stop carried by the other casing section and settable by relative adjustment of the casing sections to predetermine the range of positions which the capsule may assume, a cam mounted rotatably in said other casing section and adjustable to vary the position of said stop, a scale and cooperating pointer for indicating the adjustments ofthe cam, and means for adjusting the stop to diierent positions corresponding to ydifferent indications on the scale.

2. A barometric -fuze device comprising a spring actuated firing pin, means for releasably restraining said pin, an aneroid capsule, means operative in response to contractionof the capsule for releasing said restraining means, a stop adjustable to position the capsule bodily relatively to the ring pin to predetermine the rangey of operable positions of the capsule, said stop comprising a pivotally mounted lever having a member for adjusting it during assembly Vof the device, and manually settable means comprising a rotatable member adjustable'to vary the inclination of said lever and thereby predetermine the position of the capsule at which its contraction will operate the restraining means to release the ring'pin at any desired altitude.

3. A u barometric iuze device comprising la spring-actuated ring pin, means for releasably restraining said pin, an aneroid capsule, means operative in response to contraction of the capsule for releasing said 'restraining means, a stop comprising a lever rhaving a tail piece'and adjustable to position vthe capsule bodily relatively to the liring pin to predeterminethe range 0f operable vpositions `or the capsule, manually settable means including a circular rotatablecam for adjusting said lever to predetermine the position of the capsulev atwhichits contraction will operate the restraining' means to release the iiring pin, and a guide block on which said lever is pivotally mounted and adjustable radially of 'said cam, the tail piece of said lever resting on said cam and rotation of the latter adjusting the position of said lever. v

4. A barometric fyuze' device comprising a spring-actuated ring'pin, means for releasably restraining said pin, an aneroid capsule, means operative in response to contraction of the capsule for releasing said restraining means, a'stop comprising a lever engageable withlthe capsule and adjustable to position the capsule bodily relatively to the firing pin to predetermine the range of operable positions of the capsule,l said lever having a tail piece,` manually settable means for Vadjusting sai-d lever to predetermine the'p'osition f 5 of the capsule at which its contraction will operate the restraining means to release the firing pin, said manually settable means comprising a cam with which the tail piece of said lever engages, and a block on which said lever is pivoted and adjustable radially of said cam to vary the ratio of leverage between said lever and tail piece u and thereby vary the position of said lever at of operable positions of the capsule, said leverhaving a tail piece, manually settable means comprising a rotatable cam engaged by the tail piece of said lever for adjusting the latter to predetermine the position of the capsule at which its contraction will operate the restraining means to release the firing pin, a scale cooperative with the cam for indicating the positions into which the cam is rotated, and a block on which said lever is pivoted and adjfustable radially of the cam.

HUGH CHARLES HEBARD.

REFERENCES CITED The following references are of record in t'ne ille of this patent:

UNITED STATES PATENTS Number Name Date 1,346,127? Chanard July 13, 1920 2,119,552 Hayden Mar. 8, 1938 FOREGN PATENTS Number Country Date I 522,990 Great Britain July 2, 1940 

